1. Field
The present disclosure relates generally to fiber-reinforced resin composites and deals more particularly with a composite having fibers coated with a distortional resin.
2. Background
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Composite materials are used in aircraft to decrease the weight of the aircraft. This decreased weight improves performance features such as payload capacities and fuel efficiencies. Further, composite materials provide longer service life for various components in an aircraft.
Composite materials may be tough, light-weight materials created by combining two or more functional components. For example, a composite material may include reinforcing fibers bound in a polymeric resin matrix. The fibers may be unidirectional or may take the form of a woven cloth or fabric. The fibers and resins may be arranged and cured to form a composite material.
In fiber-reinforced composites, the efficiency of load transfer between the fiber and the surrounding matrix at the micro-scale level, may directly affect the overall mechanical performance of the composite at the continuum level. The region of the matrix that may be substantially affected by the presence of fibers, sometimes referred to as the “interphase” region, is the interfacial area of the matrix directly surrounding the fiber. In composites, this interphase region may experience high shear strain due to the mismatch in elastic stiffness between the fibers and the surrounding matrix.
Widely-used conventional bulk resins may not provide desirable distortional capabilities. As a result, various resin matrix formulations have been developed to improve the distortional capability of a polymer resin. However, formulations demonstrating higher distortional capability performance potential may have a higher cost than conventional bulk resins. Formulations demonstrating higher distortional capability may also have other undesirable limitations. These other undesirable limitations may include limited fluid resistance, low glass transition temperature, and less than desired prepreg handling characteristics such as insufficient tack and/or prepreg handling life. These undesirable limitations may be partially addressed by modifying the chemistry of the bulk polymer resin forming the matrix. However these modifications may require development of specialized monomers or additives which can add to product cost. Moreover, these specialized formulations and additives may undesirably reduce other performance properties of the composite. There is also a need for a method of making such composites that uses conventional bulk resins and avoids the need for resin additives or special resin formulations. Therefore, it would be desirable to have a method and apparatus that take into account at least one of the issues discussed above as well as possibly other issues.